Water Volume Variations Estimation and Analysis Using Multisource Satellite Data: A Case Study of Lake Victoria

The spatiotemporal changes of lake water resources objectively reflect not only the process of the water resources balance, but also the ecological environment changes in the lake area. In recent decades, climate changes and human activities have caused great impacts on the spatial distribution of the earth’s water resources and the spatiotemporal process of the surface water cycle, which has caused a series of ecological crises and environmental problems, such as the drying-up of inland lakes, the disappearance of the oasis, water shortage or flooding and water pollution. Therefore, monitoring and fully understanding the dynamic changes of lakes is of great scientific significance for grasping regional water balance, water resources management, and sustainable development of the ecological environment. In this study, we focus on using multi-source satellite data on the estimation of water volume and multi-timescale variations analysis for large scale lakes. This study combines the problems in the practical application of “African Water Action”, taking the largest lake in Africa, Lake Victoria, as the study area, and utilizes long-term serial multi-source satellite data of the past 15 years (2003–2017), including Moderate-resolution Imaging Spectroradiometer (MODIS), Jason-1/-2/-3 and Gravity Recovery and Climate Experiment (GRACE) to perform the comprehensive analysis on the water volume change estimation. Firstly, the satellite altimetry data of Jason-1/-2/-3 and MODIS imagery was used to calculate series of water level, and to extract series of water surface area, respectively. On this basis, a more accurate regression model between the area and water level variation (ΔH) was constructed. Then, the model between water volume variation (ΔV) and ΔH, derived from area-ΔH model, was applied to calculate the relative water volume of Lake Victoria. Meanwhile, terrestrial water storage (TWS) changes between 2003 and 2016, derived from GRACE data, were also used for a comparative verification of the ΔV results. The results show the long-term series change trends of ΔV and the TWS are the same. Finally, the multi-timescale analysis of water volume changes was carried out on different time scales, such as the inter-annual, inter-monthly, and variation period.

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Using Multisource Satellite Data to Investigate Lake Area, Water Level, and Water Storage Changes of Terminal Lakes in Ungauged Regions

Remote Sensing ◽

10.3390/rs13163221 ◽

2021 ◽

Vol 13 (16) ◽

pp. 3221

Author(s):

Chuanhui Zhang ◽

Aifeng Lv ◽

Wenbin Zhu ◽

Guobiao Yao ◽

Shanshan Qi

Keyword(s):

Water Level ◽

Satellite Data ◽

Water Resource Management ◽

Water Storage ◽

Integral Model ◽

Lake Area ◽

Terminal Lakes ◽

The Impact ◽

Area Data

Lake area, water level, and water storage changes of terminal lakes are vital for regional water resource management and for understanding local hydrological processes. Nevertheless, due to the complex geographical conditions, it is difficult to investigate and analyze this change in ungauged regions. This study focuses on the ungauged, semi-arid Gahai Lake, a typical small terminal lake in the Qaidam Basin. In addition to the scant observed data, satellite altimetry is scarce for the excessively large fraction of outlier points. Here, we proposed an effective and simple algorithm for extracting available lake elevation points from CryoSat-2, ICESat-2 and Sentinel-3. Combining with the area data from Landsat, Gaofen (GF), and Ziyuan (ZY) satellites, we built an optimal hypsographic curve (lake area versus water level) based on the existing short-term data. Cross-validation was used to validate whether the curve accurately could predict the lake water level in other periods. In addition, we used multisource high-resolution images including Landsat and digital maps to extract the area data from 1975 to 2020, and we applied the curve to estimate the water level for the corresponding period. Additionally, we adopted the pyramidal frustum model (PFM) and the integral model (IM) to estimate the long-term water storage changes, and analyzed the differences between these two models. We found that there has been an obvious change in the area, water level, and water storage since the beginning of the 21st century, which reflects the impact of climate change and human activities on hydrologic processes in the basin. Importantly, agricultural activities have caused a rapid increase in water storage in the Gahai Lake over the past decade. We collected as much multisource satellite data as possible; thus, we estimated the long-term variations in the area, water level, and water storage of a small terminal lake combining multiple models, which can provide an effective method to monitor lake changes in ungauged basins.

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A review of statistical methods used for developing large-scale and long-term PM2.5 models from satellite data

Remote Sensing of Environment ◽

10.1016/j.rse.2021.112827 ◽

2021 ◽

pp. 112827

Author(s):

Zongwei Ma ◽

Sagnik Dey ◽

Sundar Christopher ◽

Riyang Liu ◽

Jun Bi ◽

...

Keyword(s):

Statistical Methods ◽

Satellite Data ◽

Large Scale

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River Discharge Estimation based on Satellite Water Extent and Topography: An Application over the Amazon

Journal of Hydrometeorology ◽

10.1175/jhm-d-18-0206.1 ◽

2019 ◽

Vol 20 (9) ◽

pp. 1851-1866 ◽

Cited By ~ 2

Author(s):

Dinh Thi Lan Anh ◽

Filipe Aires

Keyword(s):

River Discharge ◽

Amazon Basin ◽

Water Cycle ◽

Large River ◽

Water Volume ◽

Discharge Estimation ◽

Three Rivers ◽

Storage Change

Abstract River discharge (RD) estimates are necessary for many applications, including water management, flood risk, and water cycle studies. Satellite-derived long-term GIEMS-D3 surface water extent (SWE) maps and HydroSHEDS data, at 90-m resolution, are here used to estimate several hydrological quantities at a monthly time scale over a few selected locations within the Amazon basin. Two methods are first presented to derive the water level (WL): the “hypsometric curve” and the “histogram cutoff” approaches at an 18 km × 18 km resolution. The obtained WL values are interpolated over the whole water mask using a bilinear interpolation. The two methods give similar results and validation with altimetry is satisfactory, with a correlation ranging from 0.72 to 0.89 in the seven considered stations over three rivers (i.e., Wingu, Negro, and Solimoes Rivers). River width (RW) and water volume change (WVC) are also estimated. WVC is evaluated with GRACE total water storage change, and correlations range from 0.77 to 0.88. A neural network (NN) statistical model is then used to estimate the RD based on four predictors (SWE, WL, WVC, and RW) and on in situ RD measurements. Results compare well to in situ measurements with a correlation of about 0.97 for the raw data (and 0.84 for the anomalies). The presented methodologies show the potential of historical satellite data (the combination of SWE with topography) to help estimate RD. Our study focuses here on a large river in the Amazon basin at a monthly scale; additional analyses would be required for other rivers, including smaller ones, in different environments, and at higher temporal scale.

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Long-term Total Water Storage Change from a SAtellite Water Cycle (SAWC) reconstruction over large south Asian basins

10.5194/hess-2019-262 ◽

2019 ◽

Author(s):

Victor Pellet ◽

Filipe Aires ◽

Fabrice Papa ◽

Simon Munier ◽

Bertrand Decharme

Keyword(s):

Water Resources ◽

Climate Variability ◽

Water Cycle ◽

Water Storage ◽

Anthropogenic Pressure ◽

Total Water ◽

Storage Change ◽

Discharge Measurements

Abstract. The Total Water Storage Change (TWSC) over land is a major component of the global water cycle, with a large influence on climate variability, sea level budget and water resources availability for human life. Its first estimates at large-scale were made available with GRACE observations for the 2002–2016 period, followed since 2018 by the launch of GRACE-FO mission. In this paper, using an approach based on the water mass conservation rule, we proposed to merge satellite-based observations of precipitation and evapotranspiration along with in situ river discharge measurements to estimate TWSC over longer time periods (typically from 1980 to 2016), compatible with climate studies. We performed this task over five major Asian basins, subject to both large climate variability and strong anthropogenic pressure for water resources, and for which long term record of in situ discharge measurements are available. Our SAtellite Water Cycle (SAWC) reconstruction provides TWSC estimates very coherent in terms of seasonal and interannual variations with independent sources of information such as (1) TWSC GRACE-derived observations (over the 2002–2015 period), (2) ISBA-CTRIP model simulations (1980–2015), and (3) multi-satellite inundation extent (1993–2007). This analysis shows the advantages of the use of multiple satellite-derived data sets along with in situ data to perform hydrologically coherent reconstruction of missing water component estimate. It provides a new critical source of information for long term monitoring of TWSC and to better understand their critical role in the global and terrestrial water cycle.

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Water recycling: a major new initiative for Melbourne - crucial for a sustainable future

Water Science & Technology ◽

10.2166/wst.2003.0671 ◽

2003 ◽

Vol 47 (7-8) ◽

pp. 57-63 ◽

Cited By ~ 6

Author(s):

M. Arbon ◽

M. Ireland

Keyword(s):

Large Scale ◽

Water Cycle ◽

Strong Support ◽

Government Support ◽

Water Recycling ◽

Recycled Water ◽

Stakeholder Consultation ◽

Sustainable Future ◽

Treated Effluent

Melbourne Water has adopted a challenging target of recycling 20 per cent of treated effluent from Melbourne's two major sewerage treatment plants by 2010. This target was adopted in response to key drivers for water recycling in the Melbourne region such as: strong support for conserving water resources and protecting marine environments; acknowledgment of recycled water as a valuable resource; greater emphasis on environmental issues and sustainable management principles; and opportunities to increase demand for recycled water through effective planning mechanisms. Issues that must be effectively addressed to meet the target include: managing public perceptions of recycled water; health and environmental concerns; lack of consensus among government agencies; high up-front costs of infrastructure; and prices of other sources of water supply not currently true costed. Melbourne Water has identified the following factors as critical in determining the success of recycling strategy: ability to demonstrate that water recycling will be important in terms of long term water cycle management; effective stakeholder consultation; gaining government support; establishing long-term, guaranteed markets for recycled water; implementing well planned, large scale recycling schemes; ability to provide a product that meets customer needs; regulatory approval; and implementation of a system that is economically viable. Water recycling initiatives are being investigated on household, local and regional levels. Over 10 proposals that will contribute to the 20 per cent recycled water target from the regional treatment plants are under various stages of development. Melbourne Water's commitment to recycling within a total water cycle management context is a vital component of this major new initiative for Melbourne and is crucial for a sustainable future.

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Trends in the Seaward Extent of Saltmarshes across Europe from Long-Term Satellite Data

Remote Sensing ◽

10.3390/rs11141653 ◽

2019 ◽

Vol 11 (14) ◽

pp. 1653 ◽

Cited By ~ 4

Author(s):

Marieke Liesa Laengner ◽

Koen Siteur ◽

Daphne van der Wal

Keyword(s):

Satellite Data ◽

Large Scale ◽

Open Water ◽

Classification Performance ◽

Environmental Drivers ◽

Decision Tree Classification ◽

Time Period ◽

Long Time ◽

Water Level Variations

Saltmarshes provide crucial functions for flora, fauna, and humankind. Thus far, studies of their dynamics and response to environmental drivers are limited in space and time. Satellite data allow for looking at saltmarshes on a large scale and over a long time period. We developed an unsupervised decision tree classification method to classify satellite images into saltmarsh vegetation, mudflat and open water, integrating additional land cover information. By using consecutive stacks of three years, we considered trends while taking into account water level variations. We used Landsat 5 TM data but found that other satellite data can be used as well. Classification performance for different periods of the Western Scheldt was almost perfect for this site, with overall accuracies above 90% and Kappa coefficients of over 0.85. Sensitivity analysis characterizes the method as being robust. Generated time series for 125 sites across Europe show saltmarsh area changes between 1986 and 2010. The method also worked using a global approach for these sites. We reveal transitions between saltmarsh, mudflat and open water, both at the saltmarsh lower edge and interior, but our method cannot detect changes at the saltmarsh-upland boundary. Resulting trends in saltmarsh dynamics can be coupled to environmental drivers, such as sea level, tidal currents, waves, and sediment availability.

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A Numerical Investigation on Tidally Induced Sediment Transport and Morphological Changes with Changing Sea Level in South-East England

Geosciences ◽

10.3390/geosciences9030140 ◽

2019 ◽

Vol 9 (3) ◽

pp. 140

Author(s):

Nicoletta Leonardi ◽

Xiaorong Li ◽

Iacopo Carnacina

Keyword(s):

Sediment Transport ◽

Sea Level Rise ◽

Water Level ◽

Sea Level ◽

Large Scale ◽

Morphological Changes ◽

Morphological Evolution ◽

Morphodynamic Equilibrium ◽

South East England

The impact of tide-induced morphological changes and water level variations on the sediment transport in a tidally dominated system has been investigated using the numerical model Delft3D and South-East England as a test case. The goal of this manuscript is to explore the long-term changes in morphology due to sea level rise and the large-scale morphodynamic equilibrium of the South-East England. Our results suggest that the long term (century scale) tidally-induced morphological evolution of the seabed slows down in time and promotes a vanishing net transport across the large scale system. Century-scale morphologically updated simulations show that both morphological changes and net transport values tend to decrease in time as the system attains a dynamic equilibrium configuration. Results further suggest that the presence of a gradual increase in mean sea level accelerates the initial morphological evolution of the system whose morphological rate of change gradually attains, however, same plateau values as in the absence of sea level rise. Given the same base morphology, increasing water levels enhance residual currents and the net transport near the coastline; and vice-versa, decreasing sea levels minimize both residuals and net transport near the coastline. The areas that are more affected by, water level and morphological changes, are the ones where the net transport is the highest. This manuscript explores and allows extending the idea of morphodynamic equilibrium at a regional scale, larger than the one for which this concept has been generally explored i.e., estuarine scale.

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Recent Evidence of Large-Scale Receding Snow Water Equivalents in the European Alps

Journal of Hydrometeorology ◽

10.1175/jhm-d-16-0188.1 ◽

2017 ◽

Vol 18 (4) ◽

pp. 1021-1031 ◽

Cited By ~ 31

Author(s):

Christoph Marty ◽

Anna-Maria Tilg ◽

Tobias Jonas

Keyword(s):

Time Series ◽

Large Scale ◽

Snow Water Equivalent ◽

Water Cycle ◽

Critical Role ◽

European Alps ◽

Measurement Series ◽

Snow Water ◽

Snow Mass

Abstract Snow plays a critical role in the water cycle of many mountain regions and heavily populated areas downstream. In this study, changes of snow water equivalent (SWE) time series from long-term stations in five Alpine countries are analyzed. The sites are located between 500 and 3000 m above mean sea level, and the analysis is mainly based on measurement series from 1 February (winter) and 1 April (spring). The investigation was performed over different time periods, including the last six decades. The large majority of the SWE time series demonstrate a reduction in snow mass, which is more pronounced for spring than for winter. The observed SWE decrease is independent of latitude or longitude, despite the different climate regions in the Alpine domain. In contrast to measurement series from other mountain ranges, even the highest sites revealed a decline in spring SWE. A comparison with a 100-yr mass balance series from a glacier in the central Alps demonstrates that the peak SWEs have been on a record-low level since around the beginning of the twenty-first century at high Alpine sites. In the long term, clearly increasing temperatures and a coincident weak reduction in precipitation are the main drivers for the pronounced snow mass loss in the past.

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Geographic variation and temporal trends in ice phenology in Norwegian lakes over a century

10.5194/tc-2020-374 ◽

2021 ◽

Author(s):

Jan Henning L’Abée-Lund ◽

Leif Asbjørn Vøllestad ◽

John Edward Brittain ◽

Ånund Sigurd Kvambekk ◽

Tord Solvang

Keyword(s):

Large Scale ◽

Regional Climate ◽

Temporal Trends ◽

Large Set ◽

Lake Area ◽

Time And Space ◽

Break Up ◽

Future Consequences ◽

Ice Phenology

Abstract. Long-term observations of ice phenology in lakes are ideal for studying climatic variation in time and space. We used a large set of observations from 1890 to 2020 of the timing of freeze-up and break-up, and the length of ice-free season, for 101 Norwegian lakes to elucidate variation in ice phenology across time and space. The dataset of Norwegian lakes is unusual, covering considerable variation in altitude (4–1401 m a.s.l.) and climate (from oceanic to continental) within a substantial latitudinal and longitudinal gradient (58.2–69.9° N; 4.9–30.2° E). The average date of ice break-up occurred later in spring with increasing altitude, latitude and longitude. The average date of freeze-up and the length of the ice-free period decreased significantly with altitude and longitude. No correlation with distance from the ocean was detected, although the geographical gradients were related to regional climate due to adiabatic processes (altitude), solar radian (latitude) and the degree of continentality (longitude). There was a significant lake area effect as small lakes froze-up earlier due to less volume. There was also a significant trend that lakes were completely frozen over later in the autumn in recent years. After accounting for the effect of long-term trends in the large-scale NAO index, a significant but weak trend over time for earlier ice break-up was detected. An analysis of different time periods revealed significant and accelerating trends for earlier break-up, later freeze-up and completely frozen lakes after 1991. Moreover, the trend for a longer ice-free period also accelerated during this period, although not significant. An understanding of the relationship between ice phenology and geographical parameters is a prerequisite for predicting the potential future consequences of climate change on ice phenology. Changes in ice phenology will have consequences for the behaviour and life cycle dynamics of the aquatic biota.

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Analysis on the influence of runoff trend in the Liusha River Basin of Xishuangbanna

E3S Web of Conferences ◽

10.1051/e3sconf/202122802010 ◽

2021 ◽

Vol 228 ◽

pp. 02010

Author(s):

Zhen Ling ◽

Shan Xu ◽

Minghua Dong ◽

Guojian Feng ◽

Hong Huo ◽

...

Keyword(s):

Water Resources ◽

River Basin ◽

River Runoff ◽

Large Scale ◽

Water Security ◽

Comparison Method ◽

Ecological Environment ◽

Rubber Plantation ◽

Natural Forests ◽

Runoff Change

In recent decades, there are lots of the changes of land use in the Liusha River basin in Xishuangbanna, Yunnan Province. The large-scale replacement of natural forests by rubber plantation have had a certain impact on the ecological environment and water resources in the Liusha River basin. Based on the data of runoff, rainfall and evaporation from 1963 to 2015 measured by Menghai Hydrological Station of Liusha River, the effects of climate change and human activities on the ecological environment of Liusha River runoff and the degree of change were analyzed by using the comparison method of slope change rate of runoff accumulation. The research results show that the cumulative amount of runoff flow after mutation presents significant decrease trend from 1963 to 2015. Because of the Liusha river runoff change decision which residents downstream watershed water security, the runoff of the ecological environment situation and analysis, the protection of natural resources such as forests and the effective protection of regional water resources sustainable development has important guiding significance.

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